Question

0

1
4
Joey enlarged a 3-inch by 5-inch photograph on a copy machine. He enlarged it four times. The table below
shows the area of the photograph after each enlargement
Enlargement
2 3
Area (square inches) 15 18.8 23.4 29.3 36.6
What is the average rate of change of the area from the original photograph to the fourth enlargement, to the
nearest tenth
1) 43
3) 5.4
2) 4.5
4) 6.0

Answer 1

3) 5.4

Explanation:

Given two points (x1, f(x1)) and (x2, f(x2)), the average rate of change is computed as follows:

[f(x2) - f(x1)]/[x2 - x1]

From the original photograph to the fourth enlargement, the points are (0, 15) and (4, 36.6). Replacing into the equation we get:

[36.6 - 15]/[4 - 0] = 5.4